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# Acoustics of a Cylindrical Vessel With Water Solution

08/23/2017 2:00 PM

Starting with this link: Breathing modes of a partially filled cylindrical vessel

SW Research Institute paper published first in February of 1962.

NASA declassified: 19 Dec 2007

Interesting effects with the fundamental, and first harmonic modes is where I begin:

(1) tank is mild steel 1/16" wall thickness (or thereabouts), 6" diameter (D), height (h) is about 10", but liquid level is about 0.5 h.

(2) contained liquid is essentially saturated bicarbonate of soda at various temperatures, so density may change somewhat, and there may be a precipitation layer at the bottom of the vessel, where also some anthracite (essentially) is resting.

Here is the question: To find the fundamental vibration frequency for the contained liquid and vessel combined by side wall excitation with a rod connected to a piezoelectric transducer, will the best mean simply be to sweep tune the excitation and observe the modes?

I feel that my ability to calculate and predict the modes is somewhat lacking, as I have not taken the time as yet, to fully absorb the mathematics involved.

I have complete faith that the math can do the job, but I am looking for a fast, and dirty way to get my answer - how to couple in the most vibrational energy to the system.

sloshing modes in carried cylindrical tank

Not quite the same, but I think the equations of motion should still hold for the most part.

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#1

### Re: Acoustics of a cylindrical vessel with water solution

08/23/2017 2:30 PM

It would seem to me that you are hampered in your efforts by the shape of the vessel...A vessel designed for maximum response would seem appropriate....so it seems you have at least three variables to work with, not including the contents of the vessel...Frequency, amplitude, and feedback....I think you need a modelling program such as flowvision...but I'm just spitballing here

http://vixra.org/pdf/1411.0596v1.pdf

https://en.wikipedia.org/wiki/Frequency_response

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97332001000300014

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#2

### Re: Acoustics of a cylindrical vessel with water solution

08/23/2017 3:30 PM

In my case, a palm spit, and thumbs up view of the reactor (which is the reactor vessel we are already presented with) is about the jist of the matter. We are only talking horseshoes and hand grenades type approximation, not a closed solution for the excitation optimization.

Heck, I am not sure whether to use a rectangular oak cross section or a poplar dowel to conduct the sound to the vessel, and whether or not to use high temperature (we will be up to 100 °C) epoxy to couple the "rod" to the vessel.

That is a very useful link, toward gaining insight how this should work, however, and I do appreciate your contributions very much.

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#4

### Re: Acoustics of a cylindrical vessel with water solution

08/23/2017 3:52 PM

Well just off the top of my head I would think that you should use a similar material to the tank itself...however a tightly drawn spring would be interesting....

You could just use one of those online frequency generators and put the tank next to the speaker, then have sensors readout to the computer in some sort of program...first with the tank empty and then filled...

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#5

### Re: Acoustics of a cylindrical vessel with water solution

08/23/2017 5:00 PM

Think Arudino IDE

void setup() {

//blah blah blah

}

void loop(){

tone (arg1, arg2, arg3);

{

//there you go

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#6

### Re: Acoustics of a cylindrical vessel with water solution

08/23/2017 5:49 PM

I don't recall if you were here for the great putter investigation, when we were tasked with finding the resonant frequency of a particular Ping putter model to replace one that had gone missing....trying to determine if the original was indeed BeCu and if there were fakes about that were brass(ugh)....Well the pitch of the Ping was particularly precise, and the proof was in the pudding...giving Lyn an excuse to procure yet another putter...

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#12

### Re: Acoustics of a cylindrical vessel with water solution

08/24/2017 9:08 AM

Yes, I do remember that discussion. It was highly entertaining.

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#3

### Re: Acoustics of a cylindrical vessel with water solution

08/23/2017 3:41 PM
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#17

### Re: Acoustics of a cylindrical vessel with water solution

08/24/2017 9:25 AM

I think picture (f) is pretty one, that I am looking for.

I will even herewith divulge my reasoning:

(1) acoustic waves should assist in dislodging gas bubbles from the electrodes in this electrolysis reactor, so it cannot hurt electrical efficiency.

(2) oscillating compression/rarefaction may distort graphitic structures just enough to stimulate intercalated protons (and other hydrogen isotopes) to undergo transformation to cold neutron plus, thus creating a NAE that is capable of releasing excess heat.

If is a mighty big word, so if for example a deuterium atom were to capture it own electron, the product would not be a cold neutron, but would be a cold dineutron.

I have seen discussions where clusters of neutrons were considered as possible, but I have zero physical experimental evidence of such things.

The generally postulated theory is something of an "aufbau" or ladder theory, where cold neutron drifts to another proton, resulting in deuteron, or cold neutron drifts to deuteron, resulting in triton (tritium nucleus), and so forth, unless an unstable hydrogen isotope forms that exists for about one nuclear oscillatory period, and falls to helium nucleus with release of the binding energy.

This is basically what Brillouin Energy is basing their equipment on, except they use gas and nickel wire, with a huge excitation current to induce electron captures.

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#18

### Re: Acoustics of a cylindrical vessel with water solution

08/24/2017 11:01 AM

Why not try your reaction in an ultrasonic cleaner? It's already been designed. They range in size for small jewelry cleaners to large industrial ones.

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#20

### Re: Acoustics of a cylindrical vessel with water solution

08/24/2017 11:18 AM

We are saving that one for later. Besides, I looked and didn't find an easy way to incorporate all the inlets and outlets, the electrode connections and all, and still put a hermetically sealed lid on it, such that electrolysis gases and vapors only go where intended. I will have to keep working on that one.

Your idea is completely sound, and clearly has merits (ultrasonic ones).

If driven high amplitude, ultrasound is easier to produce cavitations within the liquid phase. Just not sure how the electrodes (calcined shaped carbon) might hold up, but that is the nature of an experiment with a prototype.

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#27

### Re: Acoustics of a cylindrical vessel with water solution

08/24/2017 8:22 PM

A cylindrical tank half filled with liquid can be analyzed to determine the resonances. Cylindrical coordinate solutions involve Bessel functions, if I recall correctly. But when you put your experiment in there, your solution is likely "out the window". Anything besides liquid in the tank will affect the acoustics, probably in a way that can't be figured out analytically.

I'm thinking that you will just have to put a transducer in there and change the driving frequency until you get the results you want.

Good luck on your experiment. Please let us know if you find anything interesting!

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#28

### Re: Acoustics of a cylindrical vessel with water solution

08/24/2017 10:24 PM

Then suddenly!

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#30

### Re: Acoustics of a cylindrical vessel with water solution

08/25/2017 8:49 AM

Yes, one of the better papers I glanced at did involve Bessel functions with cylindrical coordinate system.

With two electrodes (of different geometry) in the vessel, it will complicate the standing waves that can result.

Right now, I am getting ready for a mockup vessel with and without the electrodes, and will be experimenting with keeping the mass down on the "rod" coupler and the "buzzer". If I can't get good excitation with a "buzzer" driven by Arduino tone, then I will try the Arduino tone generator as input to an amp, and use larger speaker, but then I get this honking big mass hanging off the side of the reactor wall, and might have to have "stereo", i.e. two speakers to keep the thing in balance.

Maybe even "wireless" speakers?? Kinda hard to get the electric power to them without hanging even more stuff off the reactor.

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#7

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/23/2017 7:29 PM

(1) tank is mild steel 1/16" wall thickness (or thereabouts), 6" diameter (D), height (h) is about 10", but liquid level is about 0.5 h.

Is that 0.5 h full or 0.5 h empty?

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#11

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/24/2017 8:55 AM

Maybe. Is that important to the accuracy of the analysis?

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#24

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/24/2017 11:42 AM

My point was that James expressed "half full" (or empty) as 0.5 h, which I thought was a great way of saying it. Please pardon me for not marking the post OT.

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#13

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/24/2017 9:09 AM

Depends on whether you (or whomever) is being optimistic, or pessimistic.

I am saying half-filled.

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#33

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/25/2017 8:15 PM

The optimist says the glass is half full.

The pessimist says the glass is half empty.

The engineer says the glass is twice as large as is it needs to be.

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#36

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/28/2017 9:10 AM

Sometimes the engineer designs in 100% free-board quite purposefully. This is one of those cases.

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#8

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/23/2017 9:09 PM

I have complete faith that the math can do the job, but I am looking for a fast, and dirty way to get my answer - how to couple in the most vibrational energy to the system.

Insonify it with an impulse, i.e., hit it with a hammer. Record reverberations with a microphone and analyze.

A less crude method might be driving a transducer and measuring the transducer impedance. As the frequency is varied, I would expect the impedance of the transducer to be minimum at resonance (it's doing less work at resonance). I'm not sure whether this is doable or not.

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#9

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/23/2017 9:43 PM

You could have a little fun and use it for target practice at the same time...

Just don't be holding this when the cops come...

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#15

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/24/2017 9:14 AM

Are you kidding me? The police around here will gladly come out to the farm and participate in acoustic excitation research

free of charge. Although, with the 0.40 cal rounds they have been carrying lately (or even the 9mm ones), I would want a dummy reactor for the "tawget"

practice to take place on. Usually shooting at a cylindrical object is a bad idea due to ricochet.

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#35

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/26/2017 12:18 PM

"...Usually shooting at a cylindrical object is a bad idea due to ricochet...."

Hmm. I guess I too would be tempted to have another donut, if my job carried a significant risk of being shot and I thought being cylindrical in shape caused bullets to ricochet off.

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#38

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/28/2017 9:16 AM

Not funny, bordering on political, so this is the only warning.

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#14

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/24/2017 9:11 AM

I like that approach, and just happen to have left the microphone and software drivers for it at the "farm" last weekend. Now if I can just get my research buddy to go ahead and set it up, and give the reactor a good ping...

Excellent idea. I am sure this will upset the reactor scales pump control, but we do have an enable/inhibit switch for the pump.

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#34

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/26/2017 9:56 AM

A smartphone has a microphone and there are lots of free spectrum analyzer apps...

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#37

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/28/2017 9:15 AM

Yes, but I am not willing to park my phone out at the farm for two weeks at a time.

Already have the microphone, and have links to free spectrum analyzer app.

I plan to find a suitable resonance, run it with microphone active, and do FFT using the app, then during experiment run time, I will use tone(P, X, T) along with noTone(P), to produce a 50% duty cycle on excitation, so I can get a "clean" spectrum of what follows the acoustic wave excitation.

If it were not for the fact I expect a large signal disparity between the excitation and any emission of sound at the same frequencies, I would simply record and compare the FFT of incoming sound, and picked up sound. It appears in science often, that one has to resort to various measures to separate the perturbation from the experiment.

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#39

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/29/2017 7:28 PM

When I upgrade my phone, I keep the old one for this kind of thing. It can still load new apps, etc, over WiFi, everything but make phone calls, 99% of what I use a smartphone for.

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#40

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/30/2017 9:14 AM

Yes, you do have a point. Hmmm...where did I put that old phone. Oh never mind, I ordered a cheap amplifier and some other bits from Amazon.

I am now considering using story hour for the reactor, perhaps in Choctaw.

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#10

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/23/2017 11:34 PM

I could come up with more than a few reasonable methods to resonate a vessel.. but what?

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#16

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/24/2017 9:15 AM

What what?

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#19

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/24/2017 11:08 AM

Once upon a time I ran across a program called Spectrogram. It did Fourier analysis of analog input signals. I was looking for resonance frequencies on string trimmers (weed whackers) We put an accelerometer on the trimmer shaft and then struck the trimmer with a rubber hammer and looked for peak frequencies in the response to the pulse. It worked like a charm.

For your application, you will have resonance responses in three dimensions, peak response vibration locations and various nodal points. If you measure response at a nodal point or in the wrong direction you will get false low readings, so you will need to take a series of readings in several locations and directions at the tank surface. It is possible that none of the readings will actually be useful to you as it appears you want to measure pressure at several locations within the working fluid to determine where the action is. Since the surface of the fluid will be damped by open channel flow pressure limitations, it sounds like the standing pressure waves will be primarily in the lateral direction at a much higher frequency regime than the vertical resonance frequencies.

Is this more of that cold fusion moonshine you have been going on about?

BTW, I am scheduled for a staycation next week to finish clearing out and organizing the shop at home and will be ready to start printing the flatulizer rotor. How is the angle detector mounting going?

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#21

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/24/2017 11:25 AM

I still have not done the angle detector surface mount as yet.

I ran into several programming snags where (very mysteriously) my Arduino sketches were not compiling. It appears to be a memory issue on a stupid HP "laptop" computer that is not much more than a doggone tablet.

As soon as I switched over to my trusty desktop - everything cleared up, same on my other Gateway laptop that has loads and loads of disk space (about 780GB). That is one nice machine, and I practically stole it from The Computer Guy here for a couple hundred bucks.

Yes, it is cold fusion "moonshine", but one needs something to do during those long winter nights down this way.

I should be getting on that this weekend (the surface mount). Heck the whole circuit board it gets mounted to is about the size of a diabetes test strip.

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#22

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/24/2017 11:27 AM

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#23

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/24/2017 11:29 AM

In the set up described, there are several things that may occur and lead to variations in resonant frequency.

Is the tank vented? What are these openings like? Size, shape, neck, placement, etc. A volume of air could approach resonance.

Tank walls will oscillate more freely above the liquid line, below the line, the liquid will load the walls and lower frequency.

As the vibrations stir the bicarbonate in the liquid, effects similar to the hot chocolate effect may also effect resonant frequency.

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#25

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/24/2017 12:03 PM

Yes the tank has a single vent that is L-shaped tube that opens near the top of lid. Small diameter with respect to vessel diameter.

We will be operating with approximately 100% head space above liquid.

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#26

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/24/2017 3:33 PM

I would try it with some soda and see how fast I could make the soda go flat....

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#29

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/25/2017 8:43 AM

Yes, I am going to be experimenting with a mock up at first, and that is a good idea.

One thing I have to be careful of is that reactor is resting upon a load cell that controls pump action to restore water level. We are in field trial #1 with the load cell/pump control program, and have already found the pump delivers more than the 50 g control band within just a couple of seconds. Next step is downsize the nozzle orifice, and add a pump recirculation loop to limit output pressure to about 10 psig. I think the pump is reaching over 20 psig with the present nozzle.

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#31

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/25/2017 3:49 PM

Maybe a pwm controller...

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#32

### Re: Acoustics of a Cylindrical Vessel With Water Solution

08/25/2017 3:55 PM

that is what the Arduino program does with its tone() function call.

Another way is to set a pin marked as output as HIGH or LOW, within a for loop.

One could envision the use of several pins this way, each sinking current through the same buzzer (piezoelectric speaker) to ground through its own current limiter of 150-250 Ω. Net result is a chord of tones, total energy about 250 mW, dissipation.

tone() only allows one tone to be called at a time, so chords are not done this way.

I am thinking Phantom of the Opera?? Or Also Sprach Zarathustra.

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